1. Field of the Invention
The present invention relates to a pivot or bearing arrangement for the pivotable control surface of a guidable missile, especially a projectile which can be fired through the intermediary of the gas pressure generated by a propellant charge.
2. Discussion of the Prior Art
A pivot bearing arrangement of the type under consideration has become known from the disclosure of German Patent No. 24 10 255. In that instance, provision is made to so arrange the control surfaces of an oversized-caliber four-bladed control surface system on a missile, as to enable it to be conducted from a position in which it is folded in parallel with the longitudinal axis of the missile, into a spread-apart or extended operative position; whereby in this operative position, there is facilitated a positioning of the applicable pair of mutually diametrically oppositely located control surfaces inclined relative to the longitudinal axis of the missile, in that a retaining ring which encompasses the missile is tilted about a diagonal axis by means of a linear control system, which axis represents the pivot axis for the positioning of the control surfaces.
Disadvantageous in th is prior art control surface pivot bearing arrangement is not only the need for the large amount of space for the setting ring which encompasses the missile, and which is fastened to the control surfaces secured against rotation relative thereto; but especially also in that no measures of any kind are provided for the sealing of the pivot support in the structure of the missile, which would facilitate the firing of the latter from a weapon barrel; for example, by means of propellant gases or compressed air. Such an instance of utilization is given when, for example, a projectile which is guidable during its final flight phase, for instance, a mortar grenade, is to be fired from a weapon barrel through the intermediary of a propellant charge. In order not to adversely influence the functions of the setting and control arrangement, there must be ensured under all circumstances, that upon the firing of the projectile from the dammed weapon barrel, the hot propellant gases which stand under a high pressure cannot penetrate through the bearing locations for the control surface into the interior of the projectile tail end structure with its setting components for the control surfaces. On the other hand, the sealing measures which are taken against the high pressures of the hot propellant gases may not lead to the point at which there must be readily afforded unacceptably high drive energies for the setting system, in order to be able to overcome the friction forces encountered due to the sealing action during the pivotal movement of the control surfaces.